Coupled Transient Thermal-Hydro-Mechanical Model with Strain-dependent Hydraulic Conductivity for Heavy Oil Formation under Steam Injection

摘要

This paper presents a coupled transient thermal-hydro-mechanical model with strain-dependent hydraulic conductivity for heavy oil formation under steam injection. 3D numerical analysis is performed for the purpose of estimating the scope of area of steam penetration into the unconsolidated sandstone formation at True Vertical Depth (TVD) depth around 200 m. This analysis is part of a pilot application of a set of Cyclic Steam Stimulation (CSS) wells, which will be converted to steam flood at a later time. The following processes are performed for simulating the coupled behavior of steam penetration in heavy oil formation: 1) Build a coupled thermal-hydro-mechanical model for simulation behavior of steam penetration in heavy oil formations. Strain-dependency properties have been introduced into the model by assigning thermal conductivity and hydraulic conductivity that both vary with related values of strain component. Strain-dependent elastic stiffness has also been implemented into the model. 2) Numerical analysis has been performed for temperature distribution caused by steam penetration with Finite Element software set. Totally 13 wells are modeled in this work. Predictions of T-contour development are made for 2 kinds of scenarios of operations of steam injection plan: First one is for the case without further steam injection but only time increase; the second one is for the case with steam injection and intermission. For both cases, there are productions of oil/liquid at other wells. The case study provides a case study for numerical modeling of steam penetration in the heavy oil formation with coupled thermal-hydro-mechanical modeling. A best practice of performing this kind of analysis with Finite Element method is presented.